catena-Poly[bis[1-chloromethyl-1,4-diazoniabicyclo[2.2.2]octane] [cadmium(II)-tri-μ-chlorido-[chloridocadmium(II)]-di-μ-chlorido-[chloridocadmium(II)]-tri-μ-chlorido] tetrahydrate]

The title compound, {(C7H15N2Cl)2[Cd3Cl10]·4H2O}n, consists of 1‐chloromethyl‐1,4‐diazoniabicyclo[2.2.2]octane dications, one‐dimensional inorganic chains of {[Cd3Cl10]4−} anions and uncoordinated water molecules. Each of the two independent CdII ions, one with site symmetry 2/m and the other with site symmetry m, is octahedrally coordinated by chloride ions (two with site symmetry m and one with site symmetry 2), giving rise to novel polymeric zigzag chains of corner‐sharing Cd‐centred octahedra parallel to the c axis. The organic cations, bisected by mirror planes that contain the two N atoms, three methylene C atoms and the Cl atom, are ordered. Hydrogen bonds (O—H...Cl and O—H...O) between the water molecules (both with O atoms in a mirror plane) and the chloride anions of neighbouring chloridocadmate chains form a three‐dimensional supramolecular network.